One of the fixed installation structures of the capacitor on the current market is: as shown in FIG. 1, it employs a structure with a gasket 7 and a nut 8. The disadvantage of such a structure is: 1) it needs a set of gasket 7 and nut 8. The anti—salt-spray-corrosion quality of the gasket 7 and the nut 8 needs to be controlled. And it is difficult to control such quality. 2) The fixed installation difficulty is big. It is even more difficult to install when the installation room is small. 3) When there is electricity leakage in the capacitor, the electricity is easy to be conducted from the fixed installation screw 21, the gasket 7 and the screw 8 to the electrical box and causes an accident.
Another fixed installation structure of the capacitor on the current market is: as shown in FIG. 2, a capacitor with fast-docking structure. The advantage of such structure is that it is easy to install and is not restricted by the installation room. But the disadvantage is: 1) an anchor-shaped flex card 5 is needed, wherein the anchor-shaped flex card 5 is made of spring steel sheet. The anti—salt-spray-corrosion quality thereof needs to be controlled. And it is difficult to control such quality. 2) The anchor-shaped flex card 5 needs to be fixed on the outer shell beforehand, which is an extra process step; 3) When there is abnormal electricity leakage in the capacitor occurs, the electricity can easily be conducted from the anchor-shaped flex card 5 to the electrical box and causes an accident.